1. Field of the Invention
The present invention relates to a differential gear train and, more particularly, to a differential gear train for a wheeled vehicle.
2. Description of the Related Art
A differential gear train is used to drive the tires of a wheeled vehicle to turn rightward or leftward. A conventional differential gear train 1 for a wheeled vehicle in accordance with the prior art shown in FIG. 6 comprises two housings 10 combined together, a driving gear 11 mounted between the housings 10, a bevel drive gear 13 pivotally mounted on an end face of the driving gear 11, a hollow shell 14 locked onto the driving gear 11, a support shaft 12 extended through the housings 10 to fix the bevel drive gear 13, another support shaft 12 extended through the housings 10 and the shell 14 to fix another bevel drive gear 13, an axle 15 mounted in the shell 14 and located between the two bevel drive gears 13, and two bevel differential gears 16 pivotally mounted on the axle 15 and intermeshing with the two bevel drive gears 13 in a staggered manner. Thus, the axle 15 is used to support the two bevel differential gears 16, and the support shafts 12 are used to support the two bevel drive gears 13.
However, the axle 15 and the support shafts 12 are not connected directly, so that the two bevel differential gears 16 and the two bevel drive gears 13 easily produce a fit deflection therebetween, thereby decreasing the precision of transmission. In addition, the two bevel differential gears 16 and the two bevel drive gears 13 easily produce a slip during transmission.